The Prism library provides loosely coupled pub/sub events using the Event Aggregator pattern.
The Event Aggregator is a portable class library that runs on .NET 4.0 or higher, Silverlight 5, Windows Phone 8, and Windows Store apps (Windows 8) and higher.
For samples that use the event aggregator see the Event Aggregation QuickStart or Stock Trader RI from the Prism for WPF download
or AdventureWorks Shopper RI from the Prism for the Windows Runtime download
Where to get Event Aggregator Binaries